Question

A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent?
(a) Thiosulphato
(b) Oxalato
(c) Glycinato
(d) Ethane-1, 2-diamine

Answer 1

Answer: (a) Thiosulphato

A chelating ligand has two or more binding donor atoms to a single metal ion e.g.,



Here $(\leftarrow )$ denotes binding site.
thiosulphato $\left(S_2{O}_3^{2-}\right)$ is not a chelating ligand because geometrically it is

not favourable for $S_2{O}_3^{2-}$ to chelate a metal ion.